Patent application title: BEVERAGE COMPRISING CATECHINS AND CAFFEINE

Abstract:

A beverage is prepared, which is a beverage containing catechins in ester
form (A, mg/L), catechins in free form (B, mg/L), and caffeine (C, mg/L),
the contents thereof being (1) (A+B)=500 to 6000 mg/L (2) (A)/(A+B)=0.7
to 1.0 (3) (A)/(C)=6 to 27,such that a high concentration of catechins
with high biological functionality, improved flavor and improved product
quality with low occurrence of sediment is maintained.

Claims:

1. A method of preparing a beverage comprising the steps of extracting
leaves of non-fermented tea, semi-fermented tea, or fermented tea with
water or hot water at 40.degree. C. to 100.degree. C. and removing from
the obtained extract 50 to 100 mass percent of catechin in ester form and
catechin in free form, then adding a tea extract to adjust the ratio of
the amount of catechin in ester form and the amount of catechin in free
form.

2. A method for preparing a beverage comprising the steps of extracting
tea leaves of non-fermented tea, semi-fermented tea, or fermented tea
with water or hot water at 40.degree. C. to 100.degree. C. and removing
from the obtained extract 50 to 100 mass percent of catechin in ester
form and catechin in free form, adding a tea extract with an amount of
catechin in ester form with respect to the total amount of catechin in
ester form and catechin in free form of not less than 0.7 to obtain a
beverage in which the amount of catechin in ester form with respect to
the total amount of catechin in ester form and catechin in free form is
0.7 to 1.0.

Description:

CROSS REFERENCE TO THE RELATED APPLICATIONS

[0001]This application is a Divisional of U.S. patent application Ser. No.
11/338,746 filed Jan. 25, 2006. The entire disclosure of the prior
application is hereby incorporated by reference.

BACKGROUND OF THE INVENTION

[0002]1. Field of the Invention

[0003]The present invention relates to a beverage which contains catechins
and has improved taste, such as low bitterness and astringency, and
suppressed occurrence of sediment and cream down.

[0006]On the other hand, methylxanthines, in particular, caffeine, can be
cited as components involved in the taste of tea beverages (in the
present invention, beverages containing tea leaf extract are collectively
referred to as tea beverages). Caffeine is believed to participate in
bitter taste/harsh taste, and a high dose of caffeine provides a beverage
with a strongly stimulating taste. Aiming for catechins' health function,
if a high dose is ingested, a high concentration of this caffeine derived
from tea ends up contained. Caffeine contained in high concentration
cannot yield positive feeling from the viewpoint of side effects and
bitter taste/harsh taste on the palate.

[0007]In recent years, with the expectation of catechins' functionality,
attention is concentrated on ingesting catechins more actively, and tea
beverages with decreased caffeine have been developed by testing
combinations of catechins and caffeine.

[0010]U.S. Pat. No. 3,507,433 (Japanese Patent Application Laid-Open No.
2001-197863) discloses a green tea extract, which is a green tea extract
having 1% of soluble solid as a base, having (a) a mixture of catechins
having a molecular weight range corresponding to an ultrafiltration
membrane made from a polymer having a nominal cutoff molecular weight of
700 to 5000 daltons, the catechin mixture containing (1) at least 130 ppm
of epicatechin, (2) at least 300 ppm of epigallocatechin, (3) at least
350 ppm of epigallocatechin gallate, and (4) at least 60 ppm of
epicatechin gallate, (b) at least 50 ppm of theanine, (c) 10 ppm or less
each of calcium, magnesium, manganese, aluminum, zinc, and iron ion, (d)
an optical density of 0.06 or less when measured at 600 nm and further
containing at least 450 ppm of caffeine.

[0011]Japanese Patent Application Laid-Open No. 2004-129669 discloses a
containered tea beverage containing (a) 320 mg/500 mL to 1300 mg/500 mL
of non-polymeric catechins and (b) caffeine, (c) the content ratio of
non-epicatechins among non-polymeric catechins being 40 to 80 mass
percent, (d) the mass ratio of non-polymeric catechins over caffeine
being 5 to 8, (e) the mass ratio of non-polymeric catechins over total
polyphenol being 0.88 to 1.0, and (f) turbidity being 0.7 or less, and
containing high concentrations of non-polymeric catechins, with decreased
bitter taste, harsh taste, and the like, and improved flavor.

[0012]Japanese Patent Application Laid-Open No. 2004-180535 discloses a
method for removing caffeine selectively from a caffeine and
catechin-containing component, in which a caffeine and
catechin-containing component is dissolved in a solution of organic
solvent and water mixed with a mass ratio of 9/1 to 1/9 and contacted
with activated charcoal.

[0014]Japanese Patent Application Laid-Open No. 2002-187848 discloses a
Camellia sinensis polyphenol fraction containing 50% to 65%
epigallocatechin-3-O-gallate, 13% to 20% epicatechin-3-O-gallate, 2% to
4% epicatechin, and 1.5% to 3% epigallocatechin, as well as 0.2% or less
caffeine, obtained by a method for extracting a polyphenol fraction from
Camellia sinensis (tea) containing 0.2 mass percent or less caffeine.

SUMMARY OF THE INVENTION

[0015]An object of the present invention is to provide a beverage that
maintains a high concentration of catechin with high biological
functionality, with improved flavor and product quality.

[0016]After earnest studies in view of the above problems, the present
inventors observed that by adjusting to a predetermined range the
concentration of catechins, the ratio of catechins in ester form to
catechins in free form, and the ratio of catechins in ester form to
caffeine in a beverage, the original flavor of the beverage-could be
retained, but with decreased astringency, bitter taste and harsh taste,
and furthermore, the occurrence of so-called sediment and cream down
could be suppressed, and therefore the present inventors devised the
present invention based on these observations.

[0017]That is to say, the present invention provides a beverage, which is
a beverage containing catechins in ester form (A, mg/L), catechins in
free form (B, mg/L), and caffeine (C, mg/L), the contents thereof being

[0018](1) (A+B)=500 to 6000 mg/L

[0019](2) (A)/(A+B)=0.7 to 1.0

[0020](3) (A)/(C)=6 to 27.

[0021]Catechins are major components contributing to the taste of tea
beverages, among which catechin in free form is believed to contribute to
the astringency of tea beverages.

[0022]In addition, catechins in ester form (EGCg, GCg, ECg, and Cg)
compared to catechins in free form (EGC, GC, EC, C, (+)C) have stronger
reactivity with other components, which is significant for health
function.

[0023]Generally, the amount of catechin in ester form contained in a tea
extract is on the order of 50% with respect to the total amount of
catechin in ester form and catechin in free form.

[0024]The present invention is a beverage that allows, by increasing the
catechin content while elevating the ratio of catechin in ester form
within a predetermined range and adjusting the ratio between caffeine and
catechin in ester form, the original flavor of the tea to be obtained
with decreased astringency, bitter taste and harsh taste, and the
catechin in ester form to be selectively and effectively ingested. In
addition, the so-called sediment and cream down can be suppressed, which
makes it an excellent beverage as a tea beverage.

DESCRIPTION OF THE PREFERRED EMBODIMENT

[0025]Hereinafter, an embodiment of a beverage of the present invention
will be described. However, the scope of the present invention is not
limited to the embodiment described below.

[0026](Beverage)

[0027]This embodiment contains catechin in ester form (A), catechin in
free form (B), and caffeine (C), the contents thereof being

[0028](1) (A)+(B)=500 to 6000 mg/L

[0029](2) (A)/[(A)+(B)]=0.7 to 1.0

[0030](3) (A)/(C)=6 to 27.

[0031]The amount of catechin in ester form (A) set in the present
invention means the total amount of EGCg, GCg, ECg, and Cg, and the
amount of catechin in free form (B) means the total amount of EGC, GC,
EC, C, and (+)C. These amounts of catechin in ester form and amounts of
catechin in free form are respectively determined by measuring with a
method using high performance liquid chromatography detecting at
ultraviolet wavelength. In addition, the amount of caffeine (C) can be
simultaneously determined with the same measurement method as for
catechin in ester form and catechin in free form.

[0032](Requirement (1))

[0033]In the beverage of the embodiment, an amount of catechin in ester
form (A) of not less than 350 mg/L is preferred, and not less than 500
mg/L is in particular preferred. In addition, an amount of 6000 mg/L or
less is preferred, 3000 mg/L or less is more preferred, 2000 mg/L or less
is in particular preferred, among which 1500 mg/L or less is especially
more preferred.

[0034]In addition, in the beverage of the embodiment, a total amount of
catechin in ester form (A) and catechin in free form (B) of not less than
500 mg/L is adequate, and a content of not less than 700 mg/L is more
preferred. In addition, an amount of 6000 mg/L or less is adequate, 3000
mg/L or less is preferred, and 2800 mg/L or less is more preferred.

[0035](Requirement (2))

[0036]In addition, a ratio of the amount of catechin in ester form (A)
with respect to the total amount of catechin in ester form (A) and
catechin in free form (B), that is (A)/[(A)+(B)], of not less than 0.7 is
adequate, not less than 0.75 is preferred, and not less than 0.8 is more
preferred. In addition, an amount of 1.0 or less is adequate.

[0037]If (A)+(B) is 500 to 6000 mg/L and (A)/[(A)+(B)] is 0.7 to 1.0 as
indicated above, a beverage can be obtained which allows catechin with
strong biological functionality to be ingested easily and inhibits
excessive astringency.

[0038](Requirement (3))

[0039]In addition, a ratio of the amount of catechin in ester form (A)
with respect to the amount of caffeine (C), that is (A)/(C), of not less
than 6 is adequate, and not less than 7 is preferred. In addition, a
ratio of 27 or less is adequate, 26.6 or less is preferred, 20 or less is
more preferred, among which 15 or less is in particular preferred. If
(A)/(C) is 6 to 27, the bitter taste and harsh taste due to caffeine can
be decreased; furthermore, the development of sediment and cream down can
be suppressed, and the visual quality can also be positive.

[0040](Preparation of Beverage)

[0041]In regard to the preparation of the beverage of the embodiments, (1)
total amount and (2) mass ratio of catechin in ester form and catechin in
free form, furthermore, (3) mass ratio of catechin in ester form and
caffeine, may be adjusted by dissolving in water catechin in ester form
(A), catechin in free form (B), and caffeine (C), so as to obtain a
predetermined concentration, respectively; in particular, in the case of
a tea beverage, extracting with water or hot water a non-fermented tea, a
semi-fermented tea, a fermented tea, or a blend thereof, and then adding
a tea extract to adjust the amount of catechin in ester form and catechin
in free form allows natural tea flavor that can be drawn out, which is
more preferred.

[0042]In addition, to prepare the beverage of the embodiment, extracting
tea leaves of non-fermented tea, semi-fermented tea, or fermented tea
with water or hot water at 40° C. to 100° C. and removing
from the obtained extract 50 to 100 mass percent of catechin in ester
form and catechin in free form, then adding the tea extract to adjust the
ratio of the amount of catechin in ester form and the amount of catechin
in free form is also preferred.

[0043]Hereinafter the preparation of the beverage will be explained in
detail.

[0044]Tea leaves to be used as source include green teas, such as Sen-cha,
Ban-cha, Gyokuro, Kamairi-cha, and Ten-cha as non-fermented tea; Oolong
teas, such as Tie Guan Yin, Huang Jin Gui, and Shui Xian as
semi-fermented tea; black teas, such as Darjeeling and Uva as fermented
tea; or two or more kinds thereof blended. Water, warm water, or hot
water, among which warm-hot water at 40° C. to 100° C. is
preferred for the extraction of non-fermented tea, semi-fermented tea,
fermented tea, or tea blend thereof, and in particular, hot water at
60° C. to 100° C. is more preferred.

[0045](Removal of Catechin in Ester Form and Catechin in Free Form during
Beverage Preparation)

[0046]Next, from the tea extract obtained as described above, a portion or
the entirety, preferably 50% to 100%, more preferably 70% to 100%, of
catechin in ester form and catechin in free form is removed temporarily
to obtain an intermediate with a portion or the entirety of catechin in
ester form and catechin in free form removed.

[0047]Examples of methods for removing catechin in ester form and catechin
in free form that can be used include tea extract treatment processes,
such as resin adsorption on a synthetic adsorption resin or the like,
membrane separation by ultrafiltration membrane or reverse osmosis
membrane, gel filtration chromatography method, and solvent extraction.

[0048]Among them, since resin adsorption using PVPP, which is a synthetic
adsorption resin, can selectively adsorb catechin in ester form and
catechin in free form, it is an excellent method for removing catechin in
ester form and catechin in free form. In addition, the method for
removing catechin in ester form and catechin in free form by adding PVPP
in the course of extracting tea leaves of non-fermented tea,
semi-fermented tea, or fermented tea in water or hot water, an invention
by the present inventors (Japanese Patent No. 3315304), is particularly
excellent. In so doing, the amount of synthetic adsorption resin PVPP can
be selected suitably according to the amount or concentration of tea
extract subjected to the treatment process.

[0049](Adjustment of the Amount of Catechin During Beverage Preparation)

[0050]Next, the ratio of the amount of catechin in ester form and the
amount of catechin in free form is adjusted by adding a tea extract to
the intermediate in which a portion or the entirety of catechin in ester
form and catechin in free form has been removed, as described above.

[0051]Herein, the tea extract may be a tea extract obtained by a method
different from the method for the intermediate. For example, the tea
extract is obtained by extracting tea leaves of non-fermented tea,
semi-fermented tea, fermented tea with water, hot water, or water soluble
organic solvent, further performing a predetermined purification and
concentrating the product, a ratio of the amount of catechin in ester
form with respect to the total amount of catechin in ester form and
catechin in free form of not less than 0.7 being preferred, not less than
0.8 being more preferred. Adding this tea extract allows a beverage in
which the amount of catechin in ester form with respect to the total
amount of catechin in ester form and catechin in free form is 0.7 to 1.0.

[0053]In particular, THEA-FLAN 90S is excellent for elevating the amount
of catechin in ester form with respect to the total amount of catechin in
ester form and catechin in free form contained in the beverage of the
embodiment since the amount of catechin in ester form with respect to the
total amount of catechin in ester form and catechin in free form is 0.99.

[0054]Note that the ratio of the amount of catechin in ester form and the
amount of catechin in free form can also be adjusted by adding one kind
or more of each of the purified catechins, in particular, catechin in
ester form EGCg, GCg, ECg, and Cg, when adding the tea extract or instead
of adding the tea extract. In addition, water or hot water can be added
to dilute.

[0055]As described above, by adding a tea extract with a predetermined
composition to an intermediate obtained after extracting tea leaves of
non-fermented tea, semi-fermented tea, or fermented tea with water or hot
water and removing 50% or 100% of catechin in ester form and catechin in
free form, the amount of catechin and the amount of caffeine, such as the
total amount (Requirement 1) and mass ratio (Requirement 2) of catechin
in ester form and catechin in free form, furthermore, the mass ratio of
catechin in ester form and caffeine (Requirement 3), can be adjusted more
easily and, in particular, the amount of catechin in ester form.

[0056]In addition, a beverage adjusted as described above is a beverage
that allows catechin with a strong biological functionality, in
particular, catechin in ester form, to be selectively and effectively
ingested, and excessive astringency to be inhibited, while continuing to
have a natural tea flavor.

[0057](Other Formulations)

[0058]The beverage of the embodiment may have mixed in additives, such as
oxidation inhibitor, emulsifying agent, preservative, pH adjuster,
flavorant, seasoning, edulcorant, acidulant, and quality stabilizer,
alone or in combination. For instance, vitamin C, vitamin E, cysteine,
and the like can be used as oxidation inhibitor, and in particular,
content of 0.005 to 0.05 mass percent in vitamin C is preferred. In
addition, for instance, glucose, fructose, isomerized liquid sugar syrup,
fructo-oligosaccharide, emulsified-oligosaccharide,
soybean-oligosaccharide, cyclodextrin, Aspartame, Momordica grosvenori
extract, and the like can be used as edulcorant, and in particular, a
content of 0.05 to 1.5 mass percent in cyclodextrin is adequate. By
mixing these additives alone or in combination, more excellent beverage
can be provided. In addition, the concentration can be adjusted by
suitably diluting with water, such that catechin, caffeine, and each
component are at the drinking concentration.

[0060]Enough taste component (theanine, various amino acids, organic
acids, and the like), aroma component (various esters, terpenes,
alcohols, aldehydes, and the like), pigment (chlorophyll, carotenoids),
and saccharide (various monosaccharides, oligosaccharides,
polysaccharides, water soluble macromolecules, and the like) that the tea
extract originally has remain in the intermediate obtained after
extracting a portion or the entirety of catechin in ester form and
catechin in free form from the tea extract, as described above.
Consequently, the intermediate has flavor and taste the tea extract
originally had and can be used as a taste composition with decreased
astringency due to catechin.

[0061]In addition, the intermediate can be diluted by suitably using water
or hot water. In addition, it can also be concentrated or solidified by
removing solvent completely. As the concentration of various components,
such as the taste component, of the diluted, concentrated, or solidified
intermediate can be adjusted, it can be used preferably as an
intermediate in the preparation of the beverage of the present invention;
furthermore, it can also be used preferably as a taste composition.

EXAMPLE

[0062]In the following, examples according to the present invention will
be shown; however, the scope of the invention is not limited to the
examples.

[0063](Measurement of Catechin in Ester Form, Catechin in Free Form, and
Caffeine)

[0064]A high performance liquid chromatography apparatus manufactured by
Waters Co. fitted with a column with an internal diameter of 4.6 mm and a
length of 250 mm (J'sphere ODS-H80, YMC Co. Ltd.) was used to perform a
gradient elution (flow rate 1.0 mL/min) with a mobile phase A solution:
5% acetonitrile (containing 0.1% phosphoric acid) and mobile phase B
solution: 50% acetonitrile (containing 0.1% phosphoric acid) for
separation at a column temperature of 40° C., and quantitation was
performed using a pre-constructed calibration curve. A sample sampled
from a beverage immediately after heat sterilization was carried out was
subjected to a 0.45 μm filter, then, 10 μL of the filtrate thereof
was injected to the high-performance liquid chromatography. The detection
wavelength was set to UV 230 nm.

[0065](Panelist Examination)

[0066]Four panelists were used to carry out an evaluation of the taste of
the beverage. A portion of the beverage was placed in the mouth, and the
degree of bitter taste and harsh taste was noted by the visual analog
scale method (the higher the number, the stronger the degree). In
addition, the occurrence of sediment and cream down and suitability as a
tea beverage from the viewpoint of the balance of taste (suitable as tea
beverage if suitability >5) were also evaluated similarly.

[0067](Evaluation of Occurrence of Sediment and Cream Down)

[0068]Occurrence of sediment and cream down was evaluated visually.

Example 1

[0069]Green tea leaves made in Japan in the amount of 1.5 g were added to
60 mL of hot water (70° C.), extracted by stirring for 5 minutes
to obtain a green tea extract; furthermore, 1 g of synthetic adsorption
resin (PVPP) was introduced, stirred for 10 minutes, then the tea leaves
and the synthetic adsorption resin were removed along with the adsorbed
catechin in ester form and catechin in free form by filtration. To this
extract, 0.5 g of cyclic oligosaccharide (manufactured by Nihon Shokuhin
Kako Co., Ltd.), 0.345 g of tea extract (THEA-FLAN 90S: manufactured by
Ito En Co., Ltd.; see Table 1 for composition), and a suitable amount of
vitamin C were added, the pH was adjusted with sodium bicarbonate, then
pure water was added to obtain a total volume of 250 mL. This solution
was ultra-filtered; furthermore, heat sterilization (135° C., 30
seconds) was carried out to prepare Beverage 1. In addition, a 250 mL
paper container was filled with this Beverage 1. The paper-containered
beverage was conserved for one year at room temperature. Immediately
before evaluation, the container was unsealed, and the beverage was
transferred to a transparent bottle container.

[0071]Beverage 3 was prepared similarly to Example 1, except that the
amount of the tea extract (THEA-FLAN 90S: manufactured by Ito En Co.,
Ltd.) was changed to 1.035 g. A 250 mL paper container was filled with
this Beverage 3.

[0072]Regarding the beverages of Examples 1 to 3, concentration of
catechin in ester form (A) (mg/L), concentration of catechin in free form
(B) (mg/L), concentration of caffeine (C) (mg/L), panelist examination
result and visual evaluation result after long-term conservation are
shown for each beverage in Table 2.

[0073]No bitter taste and harsh taste was identified in all the Beverages
1 to 3, which, in addition, were excellent beverages as tea beverages. In
addition, no occurrence of sediment and cream down due to long-term
conservation could be identified visually.

Comparative Example 1

[0074]Green tea leaves (heavily-steamed tea, Chinese product) in the
amount of 10 g was added to 1 L of warm water at 60° C. and
extracted by stirring for 10 minutes. After the extraction, the tea
leaves were removed, tea extract was cooled to below 25° C., and
the entirety was filtered by nylon filtration cloth. Thereafter, a 190 g
can container was filled with the filtrate, heat sterilized (120°
C., 10 minutes) to prepare a beverage (Comparative-1). The
can-containered beverage was conserved at room temperature for one year.
Immediately before evaluation, the container was unsealed, and the
beverage was transferred to a transparent bottle container.

[0077]The content of Beverage 3 conserved for one year at ordinary
temperature was transferred to a transparent bottle container, commercial
caffeine (manufactured by Wako Pure Chemical Industries, Ltd) was further
added so that the caffeine concentration became 2000 mg/L to prepare a
beverage (Comparative-4). The beverage was let to sit overnight at
refrigeration temperature; the next day, after returning to room
temperature, panelist examination and visual evaluation were carried out.

[0078]Regarding the beverages of Comparative Examples 1 to 4,
concentration of catechin in ester faith (A) (mg/L), concentration of
catechin in free form (B) (mg/L), concentration of caffeine (C) (mg/L),
panelist examination result and visual evaluation result are shown for
each beverage in Table 2.

[0079]Bitter taste and harsh taste were strongly identified in
Comparative-1 to Comparative-4, which were inappropriate beverages as tea
beverages. In addition, due to the influence of long-term conservation or
high caffeine ratio, notable occurrences of sediment and cream down were
visually observed.

[0080]Note that, as cream down occurs more easily by cooling, in
Comparative Example 4, a predetermined amount of caffeine was added to
Beverage 3 after long-term conservation to prepare a beverage
(Comparative-4), which was then conserved under refrigeration, and the
next day, the beverage (Comparative-4) was returned to room temperature,
and panelist examination and visual evaluation were carried out.